Exploring the convergence of natural flows for the generation of natural capital stocks in marine ecosystems

Marine ecosystems are open, complex, adaptive, and hierarchical systems highly integrated through the exchange of matter and energy flows. This flows exchange allows marine ecosystems to operate at different scales acting as dissipative structures, building natural capital stocks capable of generating several ecosystem services vital for human well-being. Humans derive a wide range of goods and services from marine ecosystems while, at the same time, generate several impacts causing biodiversity loss and seriously affecting their capacity to provide benefits to humans. Effective management strategies are crucial to conserve healthy and diverse marine and coastal ecosystems, maintain the valuable functions and services they provide, and allow for sustainable human activities. In recent years, Marine Protected Areas (MPAs) have been increasingly acknowledged worldwide as important tools to conserve biodiversity and achieve human well-being and sustainable development goals. Assessing the value of natural capital and ecosystem services is crucial to raise awareness on their importance, support conservation strategies, and ensure the sustainable management of marine ecosystems. This study aimed at calculating biomass and emergy-based indicators to assess the value of natural capital stocks in a Mediterranean MPA. The assessment was performed through a biophysical and trophodynamic environmental accounting model fed with field biomass data collected through ad hoc sampling campaigns performed in the MPA. Four main macro-habitats were investigated: sciaphilic hard bottom (coralligenous bioconstructions), photophilic hard bottom, soft bottom, and Posidonia oceanica seagrass beds. The biomass density of the main autotrophic and heterotrophic taxonomic groups identified in the four macro-habitats of the MPA was evaluated. Based on this biomass matrix, the emergy value of natural capital stocks was assessed. The Posidonia oceanica seagrass beds habitat showed the highest biophysical value (2.32·10¹⁹ sej) at MPA scale, while coralligenous bioconstructions resulted the habitat with the highest biophysical value per unit area (2.72·10¹² sej m⁻²). In addition, to complement the biophysical assessment with an economic perspective, the emergy-based indicators were converted into monetary units. The total value of natural capital of the whole MPA resulted in about 46 M€. The results of this study can support local managers and policy makers in the development of management strategies to ensure nature conservation and sustainable human activities. They can be also used as a benchmark for the assessment of natural capital value at larger scales in support of a proper consideration and inclusion of nature value into processes of policy making.     

Indicators of the ‘wild seafood’ provisioning ecosystem service based on the surplus production of commercial fish stocks

The ‘Wild Seafood’ Provisioning Service (WSPS), on which commercial fisheries rely, is probably one of the best studied marine ecosystem services due to its economic relevance and because extensive information sources exist for assessment purposes. Yet, the indicators often proposed are not suitable to describe the capacity of the ecosystem to deliver the WSPS. Therefore this study proposes surplus production (SP), a well-established concept in fisheries science, as the basis to calculate the capacity of marine ecosystems to provide the WSPS. SP is defined as the difference between stock production (through recruitment and body growth) and losses through natural mortality. This is, therefore, the production of the stock that could be harvested sustainably without decreasing the biomass. To assess the sustainability of the exploitation of the WSPS we also developed an indicator for this based on SP and compared it to existing fisheries management indicators. When both SP-based indicators showed a decreasing trend, contrasting with an increasing trend in the existing fisheries management indicators, the calculation of the SP-based indicators was scrutinized revealing that the weighting of the stocks into an aggregated indicator, strongly determines the indicator values, even up to the point that the trend is reversed. The aggregated indicators based on SP-weighted stocks can be considered complementary to existing fisheries management indicators as the former accurately reflect the capacity of the commercial fish to provide the WSPS and the sustainability of the exploitation of this service. In contrast the existing fisheries management indicators primarily reflect the performance of management towards achieving fisheries-specific policy goals.     

A tiered framework for assessing groundwater ecosystem health

The notion of ecosystem health has been widely adopted in environmental policy, particularly in the management of river systems. Despite this, even a notional understanding of ecosystem health and its assessment in connected aquifer ecosystems remains elusive. In this article, we propose a definition and provide a tiered framework for the assessment of ecosystem health in groundwater. From the literature we identify general attributes of a healthy groundwater ecosystem and from these develop primary (Tier 1) indicators of health. Where Tier 1 benchmarks are exceeded or more detailed assessment is required, we discuss a range of indicators (Tier 2) that may together generate a multimetric index of groundwater health. Our case study using samples from an alluvial aquifer in north-western New South Wales, Australia, demonstrates the utility of both tiers of the framework, and the ability of the approach to separate disturbed and undisturbed sites. The process of multimetric development is simple and our Tier 2 benchmarks determined from limited data. Nevertheless, our framework will be applicable and readily adaptable to site-specific contexts.     

Ecosystem Model Skill Assessment. Yes We Can!

Need to Assess the Skill of Ecosystem Models

Accelerated changes to global ecosystems call for holistic and integrated analyses of past, present and future states under various pressures to adequately understand current and projected future system states. Ecosystem models can inform management of human activities in a complex and changing environment, but are these models reliable? Ensuring that models are reliable for addressing management questions requires evaluating their skill in representing real-world processes and dynamics. Skill has been evaluated for just a limited set of some biophysical models. A range of skill assessment methods have been reviewed but skill assessment of full marine ecosystem models has not yet been attempted.

Northeast US Atlantis Marine Ecosystem Model

We assessed the skill of the Northeast U.S. (NEUS) Atlantis marine ecosystem model by comparing 10-year model forecasts with observed data. Model forecast performance was compared to that obtained from a 40-year hindcast. Multiple metrics (average absolute error, root mean squared error, modeling efficiency, and Spearman rank correlation), and a suite of time-series (species biomass, fisheries landings, and ecosystem indicators) were used to adequately measure model skill. Overall, the NEUS model performed above average and thus better than expected for the key species that had been the focus of the model tuning. Model forecast skill was comparable to the hindcast skill, showing that model performance does not degenerate in a 10-year forecast mode, an important characteristic for an end-to-end ecosystem model to be useful for strategic management purposes.

Skill Assessment Is Both Possible and Advisable

We identify best-practice approaches for end-to-end ecosystem model skill assessment that would improve both operational use of other ecosystem models and future model development. We show that it is possible to not only assess the skill of a complicated marine ecosystem model, but that it is necessary do so to instill confidence in model results and encourage their use for strategic management. Our methods are applicable to any type of predictive model, and should be considered for use in fields outside ecology (e.g. economics, climate change, and risk assessment).     

What is a healthy ecosystem?

Rapid deterioration of the world's major ecosystems has intensified the need for effective environmental monitoring and the development of operational indicators of ecosystem health. Ecosystem health represents a desired endpoint of environmental management, but it requires adaptive, ongoing definition and assessment. We propose that a healthy ecosystem is one that is sustainable – that is, it has the ability to maintain its structure (organization) and function (vigor) over time in the face of external stress (resilience). Various methods to quantify these three ecosystem attributes (vigor, organization, and resilience) are discussed. These attributes are then folded into a comprehensive assessment of ecosystem health. A network analysis based ecosystem health assessment is developed and tested using trophic exchange networks representing several different aquatic ecosystems. Results indicate the potential of such an ecosystem health assessment for evaluating the relative health of similar ecosystems, and quantifying the effects of natural or anthropogenic stress on the health of a particular ecosystem over time.     

Ecological indicators to capture the effects of fishing on biodiversity and conservation status of marine ecosystems

IndiSeas (“Indicators for the Seas”) is a collaborative international working group that was established in 2005 to evaluate the status of exploited marine ecosystems using a suite of indicators in a comparative framework. An initial shortlist of seven ecological indicators was selected to quantify the effects of fishing on the broader ecosystem using several criteria (i.e., ecological meaning, sensitivity to fishing, data availability, management objectives and public awareness). The suite comprised: (i) the inverse coefficient of variation of total biomass of surveyed species, (ii) mean fish length in the surveyed community, (iii) mean maximum life span of surveyed fish species, (iv) proportion of predatory fish in the surveyed community, (v) proportion of under and moderately exploited stocks, (vi) total biomass of surveyed species, and (vii) mean trophic level of the landed catch. In line with the Nagoya Strategic Plan of the Convention on Biological Diversity (2011–2020), we extended this suite to emphasize the broader biodiversity and conservation risks in exploited marine ecosystems. We selected a subset of indicators from a list of empirically based candidate biodiversity indicators initially established based on ecological significance to complement the original IndiSeas indicators. The additional selected indicators were: (viii) mean intrinsic vulnerability index of the fish landed catch, (ix) proportion of non-declining exploited species in the surveyed community, (x) catch-based marine trophic index, and (xi) mean trophic level of the surveyed community. Despite the lack of data in some ecosystems, we also selected (xii) mean trophic level of the modelled community, and (xiii) proportion of discards in the fishery as extra indicators. These additional indicators were examined, along with the initial set of IndiSeas ecological indicators, to evaluate whether adding new biodiversity indicators provided useful additional information to refine our understanding of the status evaluation of 29 exploited marine ecosystems. We used state and trend analyses, and we performed correlation, redundancy and multivariate tests. Existing developments in ecosystem-based fisheries management have largely focused on exploited species. Our study, using mostly fisheries independent survey-based indicators, highlights that biodiversity and conservation-based indicators are complementary to ecological indicators of fishing pressure. Thus, they should be used to provide additional information to evaluate the overall impact of fishing on exploited marine ecosystems.     

Long-term prediction on Baltic fish stocks based on periodicity of solar activity

The methods presently in wide use for the assessment of marine ecosystems and fish stocks cannot provide the high-quality long-term prognoses urgently needed for improved management of marine ecosystems and their fishery resources. A novel method of forecasting the long-term qualitative composition of ecosystem and fish stocks in the Baltic Sea based on the periodicity and succession of the processes: extraterrestrial factors????climate changes????regime forming factors (chiefly salinity and temperature)????ecosystems????fish stocks was used in 1989 to predict the approximate year class abundances of cod (Gadus morhua callarias), sprat (Sprattus sprattus balticus), sea herring and gulf herring (Clupea harengus membras) in the Baltic Sea for the years 1989?C2008. A comparison with actual development up to 2008 show that this prognosis was confirmed to a considerable extent. The method based on periodical fluctuations of freshwater input and the thermal regime is described. It predicts a new regime shift in the 2020s to a higher salinity and more acceptable conditions for the organisms of marine origin.     

Selecting indicator portfolios for marine species and food webs: a Puget sound case study

Ecosystem-based management (EBM) has emerged as a promising approach for maintaining the benefits humans want and need from the ocean, yet concrete approaches for implementing EBM remain scarce. A key challenge lies in the development of indicators that can provide useful information on ecosystem status and trends, and assess progress towards management goals. In this paper, we describe a generalized framework for the methodical and transparent selection of ecosystem indicators. We apply the framework to the second largest estuary in the United States - Puget Sound, Washington - where one of the most advanced EBM processes is currently underway. Rather than introduce a new method, this paper integrates a variety of familiar approaches into one step-by-step approach that will lead to more consistent and reliable reporting on ecosystem condition. Importantly, we demonstrate how a framework linking indicators to policy goals, as well as a clearly defined indicator evaluation and scoring process, can result in a portfolio of useful and complementary indicators based on the needs of different users (e.g., policy makers and scientists). Although the set of indicators described in this paper is specific to marine species and food webs, we provide a general approach that could be applied to any set of management objectives or ecological system.     

Potential stocks of reef fish-based ecosystem services in the Kuroshio Current region: Their relationship with latitude and biodiversity

The latitudinal decline of species richness is a general spatial pattern of biodiversity, and it applies to marine species as well. Based on a latitudinal gradient of marine species richness, potential stocks of marine ecosystem services are expected to be higher in lower latitudes through increment in biodiversity. However, little is known about the relationships of the marine ecosystem services with latitude and biodiversity. We estimated the latitudinal patterns and relationships with the biodiversity of potential stocks of three major reef fish-based ecosystem services (fisheries production, aquarium fish production, and recreational diving) at ten coral habitats from tropical to temperate zones in the Kuroshio Current region (8°37′N–33°24′N) using field survey data and information from relevant websites and administrative statistics. We found a latitudinal declin from south to north in potential stocks of aquarium fish production and diving in this region, whereas the peaks of fisheries production were found around both tropical and sub-tropical zones. Our results also showed strong positive effects of biodiversity on potential stocks of the three ecosystem services, highlighting the importance of conserving diverse fish species to sustain multiple services at high levels. Broad spatial patterns of the reef fish-based ecosystem services are useful as baselines for future evaluation of their changes. As the effects of climate change on reef fishes are predicted to vary among different latitude zones, our estimates of the ecosystem services infer specific management and economic actions for the respective zones against climate change.     

Assessment of coastal protection as an ecosystem service in Europe

Mapping and assessment of ecosystem services is essential to provide scientific support to global and EU biodiversity policy. Coastal protection has been mostly analysed in the frame of coastal vulnerability studies or in local, habitat-specific assessments. This paper provides a conceptual and methodological approach to assess coastal protection as an ecosystem service at different spatial–temporal scales, and applies it to the entire EU coastal zone. The assessment of coastal protection incorporates 14 biophysical and socio-economic variables from both terrestrial and marine datasets. Those variables define three indicators: coastal protection capacity, coastal exposure and human demand for protection. A questionnaire filled by coastal researchers helped assign ranks to categorical parameters and weights to the individual variables. The three indicators are then framed into the ecosystem services cascade model to estimate how coastal ecosystems provide protection, in particular describing the service function, flow and benefit. The results are comparative and aim to support integrated land and marine spatial planning. The main drivers of change for the provision of coastal protection come from the widespread anthropogenic pressures in the European coastal zone, for which a short quantitative analysis is provided.     

Cumulative biomass curves describe past and present conditions of Large Marine Ecosystems

Implementing the Ecosystem Approach in marine ecosystems is moving from preliminary steps—dedicated to defining the optimal features for indicators and developing efficient indicator frameworks—towards an operational phase where multisector marine management decisions are executed using this information. Within this operational context, emergent ecosystem properties are becoming quite promising as they have been demonstrated to be globally widespread and repeatable, and to be quite effective in detecting significant state variations of complex systems. Biomass accumulation across TLs (CumB‐TL) combines two important emergent properties of an ecosystem (energy flow, in terms of transfer efficiency, and storage, expressed as biomass), both amenable to detecting rapid ecosystem change. However, for further application, it is crucial to understand which types of drivers an indicator is sensitive to and how robust it is in relation to modifications of the external conditions and/or the system state. Here we address some outstanding questions of these CumB‐TL curves related to their sensitivity to various drivers by carrying out a global scale assessment (using data from 62 LMEs) over six decades (1950–2010). We confirm the consistency of the S‐pattern across all the LMEs, independent from latitude, ecosystem, environmental conditions, and stress level. The dynamics of the curve shape showed a tendency to stretch (i.e. decrease of steepness), in the presence of external disturbance and conversely to increase in steepness and shift towards higher TL in the case of recovery from stressed conditions. Our results suggest the presence of three main types of ecosystem dynamics, those showing an almost continuous increase in ecological state over time, those showing a continuous decrease in ecological state over time, and finally those showing a mixed behaviour flipping between recovering and degrading phases. These robust patterns suggest that the CumB‐TL curve approach has some useful properties for use in further advancing the implementation of the Ecosystem Approach, allowing us to detect the state of a given marine ecosystem based on the dynamics of its curve shape, by using readily available time series data. The value of being able to identify conditions that might require management actions is quite high and, in many respects, represents the main objective in the context of an Ecosystem Approach, with large applications for detecting and responding to global changes in marine ecosystems.     

It is the economy,stupid! Projecting the fate of fish populations using ecological–economic modeling

Four marine fish species are among the most important on the world market: cod, salmon, tuna, and sea bass. While the supply of North American and European markets for two of these species – Atlantic salmon and European sea bass – mainly comes from fish farming, Atlantic cod and tunas are mainly caught from wild stocks. We address the question what will be the status of these wild stocks in the midterm future, in the year 2048, to be specific. Whereas the effects of climate change and ecological driving forces on fish stocks have already gained much attention, our prime interest is in studying the effects of changing economic drivers, as well as the impact of variable management effectiveness. Using a process‐based ecological–economic multispecies optimization model, we assess the future stock status under different scenarios of change. We simulate (i) technological progress in fishing, (ii) increasing demand for fish, and (iii) increasing supply of farmed fish, as well as the interplay of these driving forces under different scenarios of (limited) fishery management effectiveness. We find that economic change has a substantial effect on fish populations. Increasing aquaculture production can dampen the fishing pressure on wild stocks, but this effect is likely to be overwhelmed by increasing demand and technological progress, both increasing fishing pressure. The only solution to avoid collapse of the majority of stocks is institutional change to improve management effectiveness significantly above the current state. We conclude that full recognition of economic drivers of change will be needed to successfully develop an integrated ecosystem management and to sustain the wild fish stocks until 2048 and beyond.     

生态系统价值在政策制度设计中的应用——以福州市为例

在探索生态系统价值可复制、可推广、可示范的核算模式的基础上,如何合理应用生态系统价值核算结果、形成生态系统价值政策制度应用体系、促进生态系统服务价值由“核算值”向“政策点”转化是目前亟待解决的问题。本研究以福州市经济生态生产总值(GEEP)和生态系统生产总值(GEP)核算为切入点,对GEEP进行指标筛选,并计算绿金指数和单位面积价值量,分析其在政策制度设计中的应用模式。结果表明: 污染物吸收量、物种保育更新能值、湿地重度威胁面积占比、空气负氧离子释放量、耕地占用率、海洋围填海面积占比、固碳量、释氧量、草地覆盖变化率、海岸防护面积、固体废弃物环境退化成本是显著影响福州市GEEP核算结果的指标;福州市2015和2018年绿金指数分别为1.59和1.23,均高于全国水平;福州市各生态系统单位面积价值量大小依次为湿地生态系统＞森林生态系统＞农田生态系统＞草地生态系统＞海洋生态系统。基于福州市GEEP影响因素和绿金指数、单位面积价值量,本研究构建了福州市生态系统价值核算结果“进决策、进规划、进考核、进监测”的管理制度和模式,为我国形成助推生态文明建设的长效机理机制提供了理论依据。     

Concepts and issues in marine ecosystem management

Ecosystem management means different things to different people, but the underlying concept is similar to that of the long-standing ethic of conservation. Current interest in marine ecosystem management stems from concerns about overexploitation of world fisheries and the perceived need for broader perspectives in fisheries management. A central scientific question is whether the effects of harvesting (top down) or changes in the physical environment (bottom up) are responsible for major changes in abundance.Historically, ecology, fisheries biology, oceanography, fisheries management and the fishing industry have gone somewhat separate ways. Since the 1980s, increasing attention has been given to multispecies aspects of fisheries, the linkages between oceanography and fish abundance and more holistic approaches to fisheries management.Sorting out the causes and effects of fluctuations in fish abundance is complicated by the lack of reliability of fisheries statistics. Discards, dishonesty and the inherent logistic difficulties of collecting statistics all combine to confuse interpretation. The overcapacity of fishing fleets and their unrestricted use are widely recognized as a contributing cause to overfishing and declines in fish stocks in many parts of the world.Ecosystem management, as shorthand for more holistic approaches to resource management, is, from a fisheries management perspective, centred on multispecies interactions in the context of a variable physical and chemical environment. Broader perspectives include social, economic and political elements which are best considered pragmatically as a part of the context of fisheries management.Objectives in marine ecosystem management are varied. From a biological perspective, an underlying principle of management is commonly assumed to be a sustained yield of products for human consumption. Whether that should be taken to mean that the yield should always be of the same products is less certain. Fishing commonly changes the relative abundance of species of fishes. Thus, a biological objective should specify the species mix that is desired.Concern for the maintenance of global diversity has generated a substantial literature on threatened and endangered species. In general, it has not been considered likely that marine fish species could be rendered extinct and greatest attention has been given to marine mammals, sea birds and sea turtles. The provision of marine parks and sanctuary areas are obvious first steps in providing a measure of protection, at least for the less widely ranging species.Related to the current concepts of ecosystem management are expressions such as ecosystem health and ecosystem integrity which are given a wide range of different meanings, none of which are readily translated into operational language for resource management. These and similar expressions are best assessed as rhetorical devices. The essential components of ecosystem management are sustainable yield, maintenance of biodiversity and protection from the effects of pollution and habitat degradation.Theory for marine ecosystem management has a long history in fisheries and ecological literature. Ecological models such as Lotka-Volterra equations, ECOPATH, trophic cascades and chaos theory do not give practical guidance for management. Fleet interaction and multispecies virtual population analysis models hold more promise for fisheries managers.Alaska provides particular opportunities for developing new concepts in fisheries management. Statistics of catch are good, stock assessments are at the state-of-the-art level and management has been prudent. Debate is active on the causes of substantial changes in abundance of many species including marine mammals, because substantial changes in the fisheries have been accompanied by major changes in oceanographic conditions.As elsewhere, the resultant changes may be a consequence of top-down and bottom-up effects. The bottom part is beyond human control, and ecosystem management is centred on managing the top-down or fisheries component in the context of special measures of protection for particular species.Whether that is a realistic goal depends in part on how much special protection is to be afforded to which species. Marine mammals, for example, are given high priority for special protection, but like fisheries they too may have significant roles in shaping the structure of marine ecosystems. Eventually, ecosystem management must come to grips with the question of how much protection of particular species is desirable in achieving optimal use of living marine resources.     

基于PSR的黄河河口区生态系统健康评价

根据压力-状态-响应(PSR)框架模型,从广义上定义河口区生态系统,将河口及毗邻的陆域、海域生态系统作为一个整体,从压力指标、状态指标、响应指标3个方面构建了黄河河口区生态系统健康评价的指标体系,以研究区1991年数据和相关国家标准为基准,2013年代表现况,利用综合指数法(CEI)评价了黄河河口区的生态系统健康状况。结果显示:黄河河口区生态系统健康评价的响应指数最高(0.9055),压力指数居中(0.8288),状态指数最低(0.6458),综合指数为0.7427。总体来看,与1991年相比,目前黄河河口区生态系统仍处于"健康"状态,但健康状况明显下降,其中状态指数下降最为严重。从区域轻度开发到人类活动强烈干扰阶段,黄河河口区存在过度捕捞、湿地不合理开发、浅海养殖过度及污染物排放等一系列影响生态系统健康的问题,应进行区域的生态恢复和科学管理。     

A generic aggregation approach to account for statistical uncertainty when combining multiple assessment results

The one-out-all-out approach (OOAO) for aggregating the assessments of single elements (e.g. species or ecosystem components) has found application in environmental polices such as the European Water Framework Directive or the Marine Strategy Framework Directive (MSFD). However, the OOAO has been challenged as being too pessimistic by making positive assessment results virtually impossible along the increasing number of aggregated elements. This study presents a generic approach, the probabilistic One-out-all-out approach, (pOOAO), to account for this issue and thereby reconciling the OOAO with probabilistic aggregation methods The pOOAO allows to determine the minimum number of elements (K_GES), which should meet their assessment benchmarks and thus should achieve a good status. By pre-setting a generic confidence level for each single assessment (e.g. 0.95) the binomial distribution can be used to obtain K_GES for any number of assessed elements. The pOOAO can also accommodate for the integration of assessments from multiple indicators within an element by adjusting the confidence level in relation to the number of integrated indicators. Depending on the generic confidence level as well as on the number of and integrated indicators and aggregated elements, the pOOAO is either consistent with the OOAO or allows for a certain number of negative assessment results, which are attributed to statistical uncertainty and error propagation. The pOOAO is consistent with the OOAO if the desired confidence level in the single assessment results is very high (>0.99) and/or the number of aggregated elements and integrated indicators is low. Through this flexibility the pOOAO could find wide application within integrated ecosystem assessments frameworks such as the MSFD, but would require to estimate the confidence level for each single assessment.     

Global in scope and regionally rich: an IndiSeas workshop helps shape the future of marine ecosystem indicators

This report summarizes the outcomes of an IndiSeas workshop aimed at using ecosystem indicators to evaluate the status of the world??s exploited marine ecosystems in support of an ecosystem approach to fisheries, and global policy drivers such as the 2020 targets of the Convention on Biological Diversity. Key issues covered relate to the selection and integration of multi-disciplinary indicators, including climate, biodiversity and human dimension indicators, and to the development of data- and model-based methods to test the performance of ecosystem indicators in providing support for fisheries management. To enhance the robustness of our cross-system comparison, unprecedented effort was put in gathering regional experts from developed and developing countries, working together on multi-institutional survey datasets, and using the most up-to-date ecosystem models.     

Coupled Ecosystem/Supply Chain Modelling of Fish Products from Sea to Shelf: The Peruvian Anchoveta Case

Sustainability assessment of food supply chains is relevant for global sustainable development. A framework is proposed for analysing fishfood (fish products for direct human consumption) supply chains with local or international scopes. It combines a material flow model (including an ecosystem dimension) of the supply chains, calculation of sustainability indicators (environmental, socio-economic, nutritional), and finally multi-criteria comparison of alternative supply chains (e.g. fates of landed fish) and future exploitation scenarios. The Peruvian anchoveta fishery is the starting point for various local and global supply chains, especially via reduction of anchoveta into fishmeal and oil, used worldwide as a key input in livestock and fish feeds. The Peruvian anchoveta supply chains are described, and the proposed methodology is used to model them. Three scenarios were explored: status quo of fish exploitation (Scenario 1), increase in anchoveta landings for food (Scenario 2), and radical decrease in total anchoveta landings to allow other fish stocks to prosper (Scenario 3). It was found that Scenario 2 provided the best balance of sustainability improvements among the three scenarios, but further refinement of the assessment is recommended. In the long term, the best opportunities for improving the environmental and socio-economic performance of Peruvian fisheries are related to sustainability-improving management and policy changes affecting the reduction industry. Our approach provides the tools and quantitative results to identify these best improvement opportunities.     

生态系统健康评价的研究进展

生态系统健康评价是环境管理和生态系统监控的基础,生态系统监控可促进生态系统健康评价。首先介绍了生态系统健康概念的产生,发展及其不同的内涵,并着重回顾和讨论了生态系统健康评价指标及其存在的问题,生态系统健康评价指标包括生态指标,物理化学指标,人类健康与社会经济指标3大类,生态指标是反映生态系统特征和状态的生物指标,它分为生态系统,群落和种群与个体等不同层次的指标或指标体系,物理化学指标是检测生态系统的非生物环境的指标。人类健康与社会经济指标着眼于生态系统对人类生存与社会发展的支持作用,采用经济参数和社会发展的环境压力指标等来衡量生态服务的质量与可持续性,根据其敏感程度和功能性,生态系统健康评价指标分为早期预警指标,适宜程度指标和诊断指标3类,一个完整的生态系统评价应包括上述3大类指标或指标体系,但在具体的评价实践中往往因评价目的和对象的不同而有所选择,生态系统健康评价目前有两个亟待解决的问题,如何有效确立评价标准与参照系以及如何正确区分人为压力和自然干扰。